Ms. Fluke came to national prominence after testifying before a House Democratic panel two years ago, pushing for health insurers to include contraception coverage as part of the Affordable Care Act, also known as “Obamacare."

At the time, lawmakers were looking at the ACA clause that allows religious institutions to opt out of including contraception in their health plans if they wish. Fluke talked about her experience as a student at Georgetown, a Catholic university that did not include birth control in its health coverage.

This exclusion caused “financial, emotional, and medical burdens” for female students at Georgetown, Fluke told Democrats after Republicans denied her bid to testify before a full House committee.

Shortly thereafter on his show, Mr. Limbaugh said of Fluke’s assertion, “It makes her a slut, right? It makes her a prostitute.”

Uproar followed, with some top Republicans disowning Limbaugh’s choice of words. The radio host eventually apologized, but Fluke became a hero to many on the left.

This controversy may have made Fluke famous, but it does not ensure she’ll inherit Representative Waxman’s seat. The list of well-known Democrats and independents eager for a chance to win the coastal L.A. district is long and getting longer. California’s jungle primary system, in which the top two vote-getters move to the general election regardless of their party affiliation, complicates all the contenders’ electoral strategies.

Fluke’s no carpetbagger: She moved to California following law school and passed the state bar exam two years ago. Other Democrats who have announced their intention to run include former Los Angeles controller and mayoral candidate Wendy Greuel, and state Sen. Ted Lieu, whose district largely overlaps Waxman’s.

Democrats who have said they might run include Debra Bowen, California secretary of State; and California Assemblymember Richard Bloom.

Independent Marianne Williamson, a self-help guide author, had already jumped into the race, running to Waxman’s left. TV producer Brent Roske is another independent candidate. The big question is whether ex-Republican and current independent Bill Bloomfield will run. Mr. Bloomfield, a wealthy and successful businessman, plowed $7 million of his own cash into running against Waxman in 2012. He won 46 percent of the vote – a strong showing against a legendary 40-year incumbent.

The 33rd District itself leans Democratic, but it's not as liberal as it used to be. Bloomfield did well in 2012 in part because redistricting carved much of Waxman’s liberal Los Angeles base out of the district, replacing it with heavily Republican Palos Verdes Peninsula to the south, points out election expert Charlie Cook in his Cook Political Report analysis of the 33rd.

That means Fluke’s liberal bona fides might not be enough to power her to victory.

Meantime, her nascent candidacy is sparking predictable partisan reactions. On the right, many conservatives are making some variation of the same joke.

“I see Sandra Fluke is planning a campaign for Congress. I presume she’ll want us to pay for that, too?” tweeted Sean Davis, co-founder of the conservative-leaning website The Federalist.

Meanwhile, the media are eagerly awaiting a comment on the candidacy from a certain well-known radio host.